Just mentioning the PCNSE prep YouTube series is in the process of being refreshed. New content includes PAN-OS 10.x as well as new product lines, marketing nomenclature, etc.
All stuff covered on the latest exam (and more...) for those of us who need to re-certify.
https://www.youtube.com/channel/UCmLLiVYaHYie29AT-hb48lA
I found it to be a good series for getting up to speed on 10.x since we just recently upgraded to it, and essentially skipped 9.1 altogether.
Forgot to mention. You can also join to view the PCNSE content live by webinar on Thursdays
Link: Webinar Registration - Zoom